Conversation has led mankind’s evolution, acting as a catalyst for progression from the caves to the skyscrapers, yet in our postmodern digital age, we’re still struggling to communicate effectively.

At the heart of Celeste Headlee’s new book, “We Need to Talk: How to Have Conversations That Matter,” the radio host outlines, through rigorous research, the benefits and rules of healthy conversation. Headlee doles out advice, drawing on her years of interview experience — including her own personal failures — on how we can reclaim the art of conversation.

“There was so much research,” Headlee said. “That’s partially because, when I went in search of advice to become a better conversationalist, I found that a lot of the advice out there was not good; it was not helpful. A lot of the advice was about how to pretend that you were listening to someone. How to repeat back what you just heard. How to nod and smile and say uh-huh. That’s not actually listening, that’s pretending to listen. The reason I had to read so many studies and do so much research is because I had to start from scratch.

“A lot of the research has not been on conversation,” Headlee continued. “In the scientific field, we have studied people talking, and we’ve actually studied, in detail, the act of listening. But we really have very little research on conversation.”

The digital age’s reconstruction of our communication formats has been quick, and the full ramifications are just being quantified. However, studies have long extolled the benefits of non-verbal communication, such as facial expressions, tone of voice and hand gestures, which are processed by the brain during in-person conversation, and lost in digital mediums.

“Honestly, I don’t really understand why we keep trying to come up with ways to replace conversation,” Headlee said. “That’s the one thing we do better than any other species. There are so many things that we don’t do well. There are so many things that human beings aren’t good at — why do we keep trying to find new technologies to replace the one thing that we do better than any other species on the planet? We’ve got that one down! We’re actually breaking it by trying to fix something that isn’t broken.

“Turn your technological eyes to some other field that we’re terrible at. There’s lots of them. Leave conversation alone. Whether you like hearing it or not, texting is not a conversation. It’s not. I can tell you that. It’s not my opinion. There’s no measure of effective communication texting is a replacement for. It’s simply not.”

In recent years, conversation and debate has become uncivilized, devolving into Twitter trolling and Facebook rants. We’ve seen once-civilized and intelligent debates by our leaders distilled into yelling matches, malicious quips and one-liners. Political discussions are nigh impossible to conduct without bombast or hyperbole. Headlee argues that the divisiveness in our national conversation has been fueled by the decline of healthy conversation.

“One of the most interesting findings that I read was that in fact, when you read someone’s opinion that is written down, in any form, whether it be a website, or an actual paper that you’re looking at, you’re more likely to think that someone disagrees with you because they’re stupid and ignorant,” Headlee said. “Whereas, if you hear them telling you the exact same opinion, if you hear their voice saying it to you, you’re more likely to assume they disagree with you because they have different perspectives and experiences.

“What that means is when we read an opinion, we are more likely to dehumanize the author of that opinion,” Headlee continued. “As opposed to, the human voice literally helps us humanize those who disagree. If you extrapolate that to how rarely we hear people — I am not talking about pundits, they’re all about saying things that are provocative — I am talking about regular people. We rarely hear their opinions. We almost always read them. It’s not surprising to me that we’re dehumanizing them.”

The simple answer is for us to put our phones down and talk to each other. But in our modern world, where we rely on digital communication for work as much as entertainment, that is not so simple to do. Headlee finds that a balance of technology-based and organic communication is the key to reviving the art of conversation.

“I think the first step is to really become aware of how much you’re texting and email,” Headlee said. “Because some people are in denial about how much of their phone conversations and face-to-face conversations have disappeared; how much they’ve replaced them. The second step is to say, before you send any text or email, to stop and say, is this the best platform for this message? Is this the best way to do this? Or can I pick up the phone?

“The scientific research is pretty much asserted that the gold standard of communication is voice to voice, or face to face,” Headlee said. “That doesn’t mean that there is no use for email. Email is cheap. It’s quick; if you want to send an attachment you can. You can send an entire book by email. That’s fantastic. You can send an agenda. Any time there’s any nuance or debate or emotion, email is not your best vehicle for that message.”